With the calm of global capital markets shattered in the past two weeks, the ongoing military conflict in the Middle East has taken an understandable back seat to monetary matters. And yet, tensions involving Syria, Iran and Israel continue to escalate, most notably with this weekend's outright attack by Israel on Syria, allegedly in retaliation for an Iranian drone launch from a Syrian army base, and which led to the first downing of an Israeli F-16 jet in decades.

Yet what has so far prevented the proxy way from spinning out of control, was that Putin - as guarantor of the Syria-Iran axis on one hand, and Netanyahu as his nemesis on the other, had expressed restraint. For now.

That may change, however, following a Reuters report that Russian fighters were among those killed when U.S.-led coalition forces clashed with pro-government forces in Syria earlier this month.

While Russia’s Defense Ministry said at the time that pro-government militias involved in the incident had been carrying out reconnaissance "and no Russian servicemen had been in the area", the story changed on Monday when it emerged that at least two Russian men fighting informally with pro-government forces were killed in the incident in Deir al-Zor province, their associates told Reuters.

One of the dead was named as Vladimir Loginov, a Cossack from Russia’s Kaliningrad exclave. Maxim Buga, a leader of the Cossack community there, said Loginov had been killed around Feb. 7 along with “dozens” of other Russian fighters.

The other man killed was named as Kirill Ananiev, described as a radical Russian nationalist. Alexander Averin, a spokesman for the nationalist party he was linked to, told Reuters Ananiev had been killed in shelling in the same fighting on Feb. 7.

If the deaths are confirmed, it could turn into a political scandal for Putin, with the public demanding why the government is keeping military deaths under wraps. Already Grigory Yavlinsky, a veteran liberal politician who is running for president in elections next month, has called on Putin to disclose how many Russians had been killed in Syria and in what circumstances.

“If there was large-scale loss of life of Russian citizens, the relevant officials, including the commander-in-chief of our armed forces (Putin), are obliged to tell the country about it and decide who carries responsibility for this,” Yavlinsky said in a statement released by his Yabloko party.

Of course, if indeed Russian soldiers were killed while fighting under covert circumstances - in the same way as killed US "military advisors" are kept under seal - that is the last thing Moscow would like to publicize. Unless of course the political calculus shifts, and Putin decides that it is time for a full-blown military escalation, in which case the deaths will be used as the justification behind any armed conflict.